Apparatus for producing carbon black

ABSTRACT

Apparatus for introducing charge oil and a dispersant as a mixture into a carbon black reactor to establish two zones of charge oil at different entrance velocities into the reactor.

United States Patent [191 Krejci Dec. 2, 1975 APPARATUS FOR PRODUCING CARBON BLACK [75] Inventor: Joseph C. Krejci, Phillips, Tex.

[73] Assignee: Phillips Petroleum Company,

Bartlesville, Okla.

[22] Filed: Apr. 18, 1974 [21] Appl. No.: 462,108

Related US. Application Data [62] Division of Ser. No. 1,432, Jan. 8, 1970, Pat. No.

[52] US. Cl. 23/2595; 137/604; 239/423; 239/550; 259/4; 423/450 [51] Int. Cl. C09C 1/48 [58] Field of Search 23/2595; 48/192; 239/423-434, 561, 550; 259/4, 18; 137/602, 604, 605; 423/450 [56] References Cited UNITED STATES PATENTS 2,121,948 6/1938 Borland 239/561 UX 3,060,004 10/1962 Whitsel, Jr.... 3,421,693 1/1969 Fraser 239/434 X Primary Examiner.lames H. Tayman, Jr.

[57] ABSTRACT Apparatus for introducing charge oil and a dispersant as a mixture into a carbon black reactor to establish two zones of charge oil at different entrance velocities into the reactor.

1 Claim, 6 Drawing Figures Sheet 1 of 3 U.S. Patent Dec. 2, 1975 US. Patent Dec. 2, 1975 Sheet 2 of3 3,923,465

FIG. 5

U.S. Patent Dec.2, 1975 Sheet30f3 3,923,465

FIG. 6

APPARATUS FOR PRODUCING CARBON BLACK This application is a division of copending application Ser. No. 1432, filed Jan.8, 1970, now US. Pat. No. 3,867,513.

This invention relates to carbon black production.

In one of its more specific aspects, this invention relates to the production of large particle carbon black by the furnace process, the properties of the carbon black closely approaching the properties of that carbon black produced by the thermal process.

Generally, the furnace process for the production of large particle carbon black involves dispersing a hydrocarbon feedstock as a highly concentrated mass of finely divided particles in a substantially vertically positioned reactor at temperatures within the lower range of carbon black formation and passing the hot concentrated mass of hydrocarbon and other reactants through the reactor at low velocities to produce large particle size, low structure black.

The process employs as feed, fuel, oxidants and reactants, those materials conventionally employed in the production of carbon black, in the state in which these reactants are normally employed. While vertical positioning of the reactor is not essential to the process, it is preferred since .downward flow of the make-oil may affect the carbon black formation and minimize its recirculation within the reactor.

The process employs a total air to oil ratio of from about 250 to about 450 scf per gallon. Velocities of the reactants within the reactor, based upon their chemical compositions when introduced into the reactor and upon the temperature and pressure within the reactor, are less than about 16 feet per second. The carbon black formation temperature employed is about 2400 to 2500 F. at a pressure of from about psia to about 30 psia. Aftertreating of the black is preferably conducted to obtain carbon black having a photelometer of about 90, a nitrogen surface area of from about 5 to about and a structure from about 35 to about 110.

There has now been discoveredan improvement to this process, primarilyv concerning the method of introducing the hydrocarbon feed, or charge stock, into.the reactor. This invention provides improved apparatus for carrying out such a method.

According to this invention, hydrocarbon and a dispersant are introduced into the reactor as a high velocity centrally-positioned stream and as a lower velocity peripherally-positioned stream to form two different inlet velocity masses, the central mass being introduced at from two to about six times the velocity of the peripheral mass.

According to the apparatus of this invention, there is provided a nozzle having a centrally-positioned port and. a plurality of peripherally-positioned ports, the quantity of flow from the central port being to about 80% the total flow, the velocity from the central port being from two to about six times the velocity from the peripheral ports.

In general, this invention employs the establishment of two successively positioned make-oil concentrations formed simultaneously within the reactor. Establishment of these areas of concentrated make-oil is facilitated by employment of the apparatus of this invention, one embodiment being depicted in the attached drawlngs.

The apparatus emits a mixture of a dispersant and oil, preferably atomizing air and oil, at a high velocity centrally to a plurality of peripherally emitted mixtures of the same composition ejected at lesser velocities.

It is an object of this invention to provide new carbon black apparatus.

These and other objects of this invention will be .evident from the attached drawings in which FIG. 1 illustrates one embodiment of the nozzle of this invention in elevational cross section,

FIGJ2 is a cross-sectional view through section 2--2 of FIG. 1,

FIG. 3 is a cross-sectional view through section 3-3 of FIG. 1,

FIG. 4 is a cross-sectional view through section 44 of FIG. 1, and

FIG. 5 is a cross-sectional view through section-55 of FIG. 1,

FIG. 6 is a schematic view of a conventional vertical carbon black reactor containing; the nozzle of this invention.

Referring now to the attached FIG. 1, it will be seen that the hydrocarbon charge is introduced into nozzle 1 which can be comprised of two coupled sections, introduction section 2 and mixing section 3.

Section 2 is comprised of a dispersant inlet center section 4 peripheral to which is positioned oil inlet section 5. The relationship of these sections can be reversed. As will be seen from FIG. 2, wall 10 separates the oil and air as the two materials flow through the introductory section 2 of the nozzle although they can be mixed exteriorly of the nozzle and introduced through a common conduit.

Section 4 opens into a plurality of passageways 6 which discharge into center mixing chamber 7 of mixing and discharge section 3. Similarly, section 5 opens into a plurality of passageways 8 which discharge through oil passages 9 inwardly into center mixing chamber 7. Having been deflected inwardly, the oil is mixed with the air, there being formed in zone 15 a uniform mixture of airand oil. As will be seen from FIGS. 3 and 4, air passageways 6 can be positioned adjacent the outlet oil passages 9. Passages 9 are formed in face 11 and the oil passes therefrom into zone 15. By passing the one fluid into-the other, a thorough mixing of the air and oil results in zone 15.

Referring again to FIG. 1, the air-oil mixture from zone 15 passes into the plurality of the peripheral outlets 14 and into center outlet 12. Distribution is made between these peripheral outlets and the center outlet by sizing orifices 13 leading into peripheral outlets 14 so as to obtain the desired distribution between center outlet 12 and peripheral outlet 14. However, having passed through orifices 13, the air-oil mixture passes into peripheral outlets 14, the total area of outlets 14 being related to the area of outlet 12, to secure the velocities desired. Hence, both quantity and velocity distribution is obtained, the velocity of the air-oil mixture through center outlet 12 being from about two to about six times that of the velocity of the peripheral outlets l4. Orifices 13 act as restricted flow areas in communication with peripheral outlets 14 which act as peripherally-positioned conduits. The total area of these restricted flow areas can be substantially equal tothe area of the centrally-positioned conduit or outlets,- with the total area of the peripherally-positioned outlets can be from about two to about six times the area of the centrally-positioned conduit or outlet. In the preferred embodiment, the total discharge: area of the centrallypositioned conduit'is about one-third of the total area of the peripherally-positioned conduits.

peripheral outlets 14 to restriction orifices 13 as situated peripheral to center outlet 12.

Referring to FIG. 6, there is shown a vertical carbon black reactor 16 having therein nozzle 1.

The nozzle described establishes air-oil mixtures which are introduced into the reactor peripherally to a centrally-introduced air-oil mixture, the centrallyintroduced stream being introduced at a greater velocity than that of the peripherally-introduced streams. Inasmuch as the heat for promoting the pyrolytic decomposition of these streams must penetrate inwardly of these peripherally-introduced streams, it will be seen that the peripheral streams act to shield the central stream. This shielding, and the introduction of the central stream at the greater velocity, allows the centrallyintroduced stream to enter the reactor to a considerable distance before undergoing decomposition com- In base Run No. l, axial air was introduced circumferentially of the nozzle and as atomizing air, all air-oil streams from the nozzle being emitted at the same velocity, there being no center outlet stream shielded by peripherally emitted outlet streams. 1n the balance of the runs in which the method and apparatus of this invention were employed, axial air was also introduced circumferentially of the nozzle from which was emitted a high velocity central stream surrounded by the lower velocity peripheral streams.

Primary, or first, air and fuel gas were introduced through the periphery of the reactor just downstream of the point of discharge of the air-oil streams from the nozzle. A second stream of air was introduced tangentially into the reactor downstream of the primary air introduction. In all instances, an alkali metal salt was introduced for carbon black structure control, and the reaction mass was quenched in the downstream portion of the reactor to obtain a carbon black having a 90 parable to that to which the peripheral streams are sub: 20 photelometer.

jected immediately upon their ejection from the nozzle.

Results were as follows:

TABLE I Base Run Run No. I 11 111 IV V VI VII Oil Charge Rate, GPH 93 91 84.4 97 93 95 91 Dispersant Air, SCFH 4,000 4,000 2,000 6,000 4,000 4,000 4,000 Axial Air, SCFl-l 5,000 5,000 5,000 5,000 5,000 5,000 5,000 Central Outlet Velocity, ft./sec.* None 1,020 510 1,530 1,020 1,020 1,020 Peripheral Outlet Ve1ocity,.ft./sec.* 1,030 340 170 510 340 340 340 Oil Preheat Temperature, F. 400 400 410 400 375 425 375 First Tangential Air, SCFH 20,000 20,000 20,000 20,000 15,000 30,000 30,000 Tangential Fuel Gas, SCI-H 1,300 1,300 1,300 1,300 1,100 1,300 1,300 Second Tangential Air, SCFH 9,900 9,900 10,000 10,000 15,000 0 Dispersant Air/Oil, SCF/gal. 43 44 23.7 61.8 43 42 44 Air/Oil, SCF/gal. 418 428 422 423 419 412 428 Alkali Metal Additive, K 'ppm 953 812 789 838 796 780 810 Carbon Black Properties:

Nitrogen Surface Area, m lgm. 16.7 21.06 19.8 18.6 19.2 19.8 19.0

Structure, DBP, cc/100 gm. 31.4 30 33 30 29.5 32.4 31.0

Photelometer 89 94 93 95 88 90 89 Carbon Black Yield, No./gal. Make-oil 5.4 5.1 5.1 5.2 4.9 5.2 5.1

' Calculated values at standard pressure and temperature.

The dispersant which can beintroduced through the above-described nozzle can be any gaseous material including air, oxygen enriched air, an inert gas, or the like, but will be preferably air. The air so introduced can be in addition to that air which can be introduced elsewhere into the reactor, either near the introduction of the make-oil or at points downstream therefrom, or at a combination of points.

While any plurality of peripheral streams can be employed, it is preferable that at least four be used. Similarly, a plurality of centrally positioned ports can be employed, although a single port is preferred.

The fluid introduced as the dispersant will preferably be introduced in a quantity from about to about 75 scf per gallon of make-oil. The make-oil will preferably be introduced in the liquid phase and can be preheated.

The nozzle will be designed to emit about to about 80 percent of its total air-oil mixture through the center outlet, it being preferred that at least 50 percent be emitted through the center outlet. That material emitted through the center outlet should have imparted to it a velocity of from about 2 to about 6 times that velocity imparted tothe air-oil mixture emitted from the peripheral outlets. Preferably, the velocity through the center outlet should approach sonic velocity at the prevailing conditions.

The following data indicate the operation of this vention. All runs were made in a vertical reactor.

It will be seen from the above that the use of adispersant and oil mixture to establish two concentrations of make-oil within the reactor appreciably affects the surface area of the black under otherwise comparable conditions. It will also be seen that there is produced a carbon black having, at a photelometer of at least 90, a surface area of from about 19 to about 27 and a structure of from about 25 to about 34.

The above data includes values for the velocity :of the center stream and velocities for the peripheral or annular streams issued from the nozzles. These values are relative only, having been calculated on the basis of the volumes involved under standard conditions of temperature and pressure. While values higher than sonic velocity are indicated, it is believed that while sonic velocity may be approached, it is in no instance exceeded.

In the above data, the streams of the air-oil mixture emitted peripheral to the center stream were parallel to the axis of the reactor and to the center stream. However, discharge of these peripheral streams can be made angularly to the center stream, either divergently or convergently.

The carbon black produced by the method of this invention, specifically that produced in Run No. 11, Table I, has been compared with that black produced in Run No. 1, Table 1, and with Medium Thermal Black, (MT), ASTM N990, by incorporation in a natural rubber recipe on which rubber data were determined.

The natural rubber recipe was as follows:

TABLE II Parts Component by Weight Liberian Crepe Natural Rubber l Carbon Black 75 Stearic Acid 3 Sulfur 2.5 Zinc Oxide 5 Altax Accelerator (Benzothiazyl disulfide) 0.6

The results obtained on the resulting rubbers were as follows:

It will be seen from the above that the black produced according to the method of this invention resulted in a higher tensile strength and a lower 300 percent modulus in the rubber produced than did that black produced in Base Run I. It will be further noted that while the MT Black has an N SA of 8 and a structure of 35, the black of this invention was comparable to the MT black in respect to thehysteresis properties of the rubber blend, that is, in respect to the A T and the resilience results. This is unexpected inasmuch as it is generally accepted that high surface area blacks impart to rubber blends poorer hysteresis properties than do low surface blacks. Hence, it is seen that the black of this invention imparts to rubber blends unexpectedly high hysteresis properties.

It has been found that the discharge method and apparatus of this invention contribute significantly to reducing carbon deposition on the reactor walls and to the elimination of grit formation due to spalling of the reactor refractory.

It will be evident from the foregoing that various modifications can be made to both the method and apparatus of this invention. For example, a plurality of centrally-positioned streams can be emitted at the high velocities surrounded by the plurality of the low velocity streams, rather than the singly emitted high velocity stream discussed above. However, such modifications are considered as being within the scope of the invention.

What is claimed is:

1. In a carbon black reactor, a nozzle comprising a surrounding first wall means forming a mixing chamber; a second wall means having a plurality of inlet conduit means opening into said mixing chamber, said inlet conduit means comprising a plurality of centrally positioned first inlet conduits and a plurality of second inlet conduits positioned peripherally to said first inlet conduits, said second inlet conduits being provided with discharge ends which enter said mixing chamber in generally radially inwardly extending directions so that fluid introduced through said second inlet conduits converges toward fluid introduced through said first inlet'conduits to provide mixing in said mixing chamber; third wall means containing at least one central discharge conduit opening from said mixing chamber, a plurality of second discharge conduits opening from said mixing chamber and being positioned peripherally to said central discharge conduit, each of said second discharge conduits having an orifice in the inlet thereof, the total cross-sectional area of said orifices in said second discharge conduits being substantially equal to the cross-sectional area of said at least one central discharge conduit, the total of the cross-sectional areas of said second discharge conduits downstream from said orifices being from about 2 to about 6 times the cross-sectional area of said at least one central discharge conduit. 

1. IN A CARBON BLACK REACTOR, A NOZZLE COMPRISIG A SURROUNDING FIRST WALL MEANS FORMING A MIXING CHAMBER, A SECOND WALL MEANS HAVING A PLURALITY OF INLET CONDUIT MEANS OPENING INTO SAID MIXING CHAMBER, SAND INLET CONDUIT MEANS COMPRISING A PLURALITY OF CENTRALLY POSITIONED FIRST INLET CONDUITS AND A PLURALITY OF SECOND INLET CONDUITS POSITIONED PERIPHERALLY TO SAID FIRST INLET CONDUITS, SAID SECOND INLET CONDUITS BEING PROVIDED WITH DISCHARGE ENDS WHICH ENTER SAID MIXING CHAMBER IN GENERALLY RADIALLY INWARDLY EXTENDING DIRECTIONS SO THAT FLUID INTRODUCED THROUGH SAID SECOND INLET CONDUITS CONVERGES TOWARD FLUID INTRODUCED THROUGH SAID FIRST INLET CONDUITS TO PROVIDE MIXING IN SAID MIXING CHAMBR, THIRD WALL MEANS CONTIANING AT LEAST ONE CENTRAL DISCHARGE CONDUIT OPENING FROM SAID MIXING CHAMBER, A PLURALITY OF SECOND DISCHARGE CONDUITS OPENING FROM SAID MIXING CHAMBER AND BEING POSITIONED RERIPHERALLY TO SAID CENTRAL DISCHARGE CONDUIT, EACH OF SAID SECOND DISCHARGE CONDUIS HAVING AN ORIFICE IN THE INLET THEREOF, THE TOTAL CROSS-SECTIONAL AREA OF SAID ORIFICES IN SAID SECOND DISCHARGE CONDUITS BEING SUBSTANTIALLY EQUAL TO THE CROSS SECTIONAL AREA OF SAID AT LEAST ONE CENTRAL DISCHARGE CONDUIT, THE TOTAL OF THE CROSS-SECTIONAL AREAS OF SAID SECOND DISCHARGE CONDUITS DOWNSTREAM FROM SAID ORIFICES BEING FROM ABOUT 2 TO ABOUT 6 TIMES THE CROSS-SECTIONAL AREA OF SAID AT LEAST ONE CENTRAL DISCHARGE CONDUIT. 